Threads can normally exit without a explicit pthread_exit call.
There seem to date to old glibc bugs, many around 2.2.5.
The semi related bug was https://bugs.mysql.com/bug.php?id=82886.
To improve safety in the signal handlers DBUG_* code was removed.
These where also needed to avoid some MSAN unresolved stack issues.
This is effectively a backport of 2719cc4925.
These tests rely on THR_KEY_mysys but it is not initialized. On
Linux, the corresponding thread variable is null, but on macOS it has a
nonzero value. In all cases, initialize the variable explicitly by
calling MY_INIT and my_end appropriately.
Partial commit of the greater MDEV-34348 scope.
MDEV-34348: MariaDB is violating clang-16 -Wcast-function-type-strict
The functions queue_compare, qsort2_cmp, and qsort_cmp2
all had similar interfaces, and were used interchangable
and unsafely cast to one another.
This patch consolidates the functions all into the
qsort_cmp2 interface.
Reviewed By:
============
Marko Mäkelä <marko.makela@mariadb.com>
The problem was that when using clang + asan, we do not get a correct value
for the thread stack as some local variables are not allocated at the
normal stack.
It looks like that for example clang 18.1.3, when compiling with
-O2 -fsanitize=addressan it puts local variables and things allocated by
alloca() in other areas than on the stack.
The following code shows the issue
Thread 6 "mariadbd" hit Breakpoint 3, do_handle_one_connection
(connect=0x5080000027b8,
put_in_cache=<optimized out>) at sql/sql_connect.cc:1399
THD *thd;
1399 thd->thread_stack= (char*) &thd;
(gdb) p &thd
(THD **) 0x7fffedee7060
(gdb) p $sp
(void *) 0x7fffef4e7bc0
The address of thd is 24M away from the stack pointer
(gdb) info reg
...
rsp 0x7fffef4e7bc0 0x7fffef4e7bc0
...
r13 0x7fffedee7060 140737185214560
r13 is pointing to the address of the thd. Probably some kind of
"local stack" used by the sanitizer
I have verified this with gdb on a recursive call that calls alloca()
in a loop. In this case all objects was stored in a local heap,
not on the stack.
To solve this issue in a portable way, I have added two functions:
my_get_stack_pointer() returns the address of the current stack pointer.
The code is using asm instructions for intel 32/64 bit, powerpc,
arm 32/64 bit and sparc 32/64 bit.
Supported compilers are gcc, clang and MSVC.
For MSVC 64 bit we are using _AddressOfReturnAddress()
As a fallback for other compilers/arch we use the address of a local
variable.
my_get_stack_bounds() that will return the address of the base stack
and stack size using pthread_attr_getstack() or NtCurrentTed() with
fallback to using the address of a local variable and user provided
stack size.
Server changes are:
- Moving setting of thread_stack to THD::store_globals() using
my_get_stack_bounds().
- Removing setting of thd->thread_stack, except in functions that
allocates a lot on the stack before calling store_globals(). When
using estimates for stack start, we reduce stack_size with
MY_STACK_SAFE_MARGIN (8192) to take into account the stack used
before calling store_globals().
I also added a unittest, stack_allocation-t, to verify the new code.
Reviewed-by: Sergei Golubchik <serg@mariadb.org>
my_b_encr_write(): Initialize also block_length, and at the same time
last_block_length, so that all 128 bits can be initialized with fewer
writes. This fixes an error that was caught in the test
encryption.tempfiles_encrypted.
test_my_safe_print_str(): Skip a test that would attempt to
display uninitialized data in the test unit.stacktrace.
Previously, our CI did not build unit tests with MemorySanitizer.
handle_delayed_insert(): Remove a redundant call to pthread_exit(0),
which would for some reason cause MemorySanitizer in clang-19 to
report a stack overflow in a RelWithDebInfo build. This fixes a
failure of several tests.
Reviewed by: Vladislav Vaintroub
Without the call to my_mutex_init, the mutex attributes
my_fast_mutexattr and my_errorcheck_mutexattr are uninitialized.
Linux tolerates this but FreeBSD doesn't (and segfaults).
We fix for all since the unit text should be testing the
standard mutexes of the system.
- ZLIB_LIBRARIES, not ZLIB_LIBRARY
- ZLIB_INCLUDE_DIRS, not ZLIB_INCLUDE_DIR
For building libmariadb, ZLIB_LIBRARY/ZLIB_INCLUDE_DIR are still defined
This workaround will be removed later.
In our unit test, let us rely on our own reference
implementation using the reflected
CRC-32 ISO 3309 and CRC-32C polynomials. Let us also
test with various lengths.
Let us refactor the CRC-32 and CRC-32C implementations
so that no special compilation flags will be needed and
that some function call indirection will be avoided.
pmull_supported: Remove. We will have pointers to two separate
functions crc32c_aarch64_pmull() and crc32c_aarch64().
I checked all stack overflow potential problems found with
gcc -Wstack-usage=16384
and
clang -Wframe-larger-than=16384 -no-inline
Fixes:
Added '#pragma clang diagnostic ignored "-Wframe-larger-than="'
to a lot of function to where stack usage large but resonable.
- Added stack check warnings to BUILD scrips when using clang and debug.
Function changed to use malloc instead allocating things on stack:
- read_bootstrap_query() now allocates line_buffer (20000 bytes) with
malloc() instead of using stack. This has a small performance impact
but this is not releant for bootstrap.
- mroonga grn_select() used 65856 bytes on stack. Changed it to use
malloc().
- Wsrep_schema::replay_transaction() and
Wsrep_schema::recover_sr_transactions().
- Connect zipOpen3()
Not fixed:
- mroonga/vendor/groonga/lib/expr.c grn_proc_call() uses
43712 byte on stack. However this is not easy to fix as the stack
used is caused by a lot of code generated by defines.
- Most changes in mroonga/groonga where only adding of pragmas to disable
stack warnings.
- rocksdb/options/options_helper.cc uses 20288 of stack space.
(no reason to fix except to get rid of the compiler warning)
- Causes using alloca() where the allocation size is resonable.
- An issue in libmariadb (reported to connectors).
MDEV-33502 Slowdown when running nested statement with many partitions
caused this error as I failed to take into account bigendian architectures.
This patch also introduces bitmap_import() and bitmap_export() to be used
when one wants to store bitmaps in files/logs in a portable way.
Reviewed-by: Kristian Nielsen <knielsen@knielsen-hq.org>
MDEV-33502 Slowdown when running nested statement with many partitions
This change was triggered to help some MariaDB users with close to
10000 bits in their bitmaps.
- Change underlaying storage to be 64 bit instead of 32bit.
- This reduses number of loops to scan bitmaps.
- This can cause some bitmaps to be 4 byte large.
- Ensure that all not used top-bits are always 0 (simplifes code as
the last 64 bit storage is not a special case anymore).
- Use my_find_first_bit() to find the first set bit which is much faster
than scanning trough things byte by byte and then bit by bit.
Other things:
- Added a bool to remember if my_bitmap_init() did allocate the bitmap
array. my_bitmap_free() will only free arrays it did allocate.
This allowed me to remove setting 'bitmap=0' before calling
my_bitmap_free() for cases where the bitmap's where allocated externally.
- my_bitmap_init() sets bitmap to 0 in case of failure.
- Added 'universal' asserts to most bitmap functions.
- Change all remaining calls to bitmap_init() to my_bitmap_init().
- To finish the change from 2014.
- Changed all usage of uint32 in my_bitmap.h to my_bitmap_map.
- Updated bitmap_copy() to handle bitmaps of different size.
- Removed const from bitmap_exists_intersection() as this caused casts
on all usage.
- Removed not used function bitmap_set_above().
- Renamed create_last_word_mask() to create_last_bit_mask() (to match
name changes in my_bitmap.cc)
- Extended bitmap-t with test for more bitmap functions.
The patch for "MDEV-25440: Indexed CHAR ... broken with NO_PAD collations"
fixed these scenarios from MDEV-26743:
- Basic latin letter vs equal accented letter
- Two letters vs equal (but space padded) expansion
However, this scenario was still broken:
- Basic latin letter (but followed by an ignorable character)
vs equal accented letter
Fix:
When processing for a NOPAD collation a string with trailing ignorable
characters, like:
'<non-ignorable><ignorable><ignorable>'
the string gets virtually converted to:
'<non-ignorable><ignorable><ignorable><space><space><space>...'
After the fix the code works differently in these two cases:
1. <space> fits into the "nchars" limit
2. <space> does not fit into the "nchars" limit
Details:
1. If "nchars" is large enough (4+ in this example),
return weights as follows:
'[weight-for-non-ignorable, 1 char] [weight-for-space-character, 3 chars]'
i.e. the weight for the virtual trailing space character now indicates
that it corresponds to total 3 characters:
- two ignorable characters
- one virtual trailing space character
2. If "nchars" is small (3), then the virtual trailing space character
does not fit into the "nchar" limit, so return 0x00 as weight, e.g.:
'[weight-for-non-ignorable, 1 char] [0x00, 2 chars]'
Adding corresponding MTR tests and unit tests.
Checking for kill with thd_kill_level() or check_killed() runs apc
requests, which takes the LOCK_thd_kill mutex. But this is dangerous,
as checking for kill needs to be called while holding many different
mutexes, and can lead to cyclic mutex dependency and deadlock.
But running apc is only "best effort", so skip running the apc if the
LOCK_thd_kill is not available. The apc will then be run on next check
of kill signal.
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>
- Adding a new argument "flag" to MY_COLLATION_HANDLER::strnncollsp_nchars()
and a flag MY_STRNNCOLLSP_NCHARS_EMULATE_TRIMMED_TRAILING_SPACES.
The flag defines if strnncollsp_nchars() should emulate trailing spaces
which were possibly trimmed earlier (e.g. in InnoDB CHAR compression).
This is important for NOPAD collations.
For example, with this input:
- str1= 'a ' (Latin letter a followed by one space)
- str2= 'a ' (Latin letter a followed by two spaces)
- nchars= 3
if the flag is given, strnncollsp_nchars() will virtually restore
one trailing space to str1 up to nchars (3) characters and compare two
strings as equal:
- str1= 'a ' (one extra trailing space emulated)
- str2= 'a ' (as is)
If the flag is not given, strnncollsp_nchars() does not add trailing
virtual spaces, so in case of a NOPAD collation, str1 will be compared
as less than str2 because it is shorter.
- Field_string::cmp_prefix() now passes the new flag.
Field_varstring::cmp_prefix() and Field_blob::cmp_prefix() do
not pass the new flag.
- The branch in cmp_whole_field() in storage/innobase/rem/rem0cmp.cc
(which handles the CHAR data type) now also passed the new flag.
- Fixing UCA collations to respect the new flag.
Other collations are possibly also affected, however
I had no success in making an SQL script demonstrating the problem.
Other collations will be extended to respect this flags in a separate
patch later.
- Changing the meaning of the last parameter of Field::cmp_prefix()
from "number of bytes" (internal length)
to "number of characters" (user visible length).
The code calling cmp_prefix() from handler.cc was wrong.
After this change, the call in handler.cc became correct.
The code calling cmp_prefix() from key_rec_cmp() in key.cc
was adjusted according to this change.
- Old strnncollsp_nchar() related tests in unittest/strings/strings-t.c
now pass the new flag.
A few new tests also were added, without the flag.
Also fixes:
MDEV-27768 MDEV-25440: Assertion `(cs->state & 0x20000) == 0' failed in my_strnncollsp_nchars_generic_8bit
The "strnncollsp_nchars" virtual function pointer for tis620_thai_nopad_ci
was incorrectly initialized to a generic function
my_strnncollsp_nchars_generic_8bit(), which crashed on assert.
Implementing a tis620 specific function version.
Summary of changes
- MD_CTX_SIZE is increased
- EVP_CIPHER_CTX_buf_noconst(ctx) does not work anymore, points
to nobody knows where. The assumption made previously was that
(since the function does not seem to be documented)
was that it points to the last partial source block.
Add own partial block buffer for NOPAD encryption instead
- SECLEVEL in CipherString in openssl.cnf
had been downgraded to 0, from 1, to make TLSv1.0 and TLSv1.1 possible
(according to https://github.com/openssl/openssl/blob/openssl-3.0.0/NEWS.md
even though the manual for SSL_CTX_get_security_level claims that it
should not be necessary)
- Workaround Ssl_cipher_list issue, it now returns TLSv1.3 ciphers,
in addition to what was set in --ssl-cipher
- ctx_buf buffer now must be aligned to 16 bytes with openssl(
previously with WolfSSL only), ot crashes will happen
- updated aes-t , to be better debuggable
using function, rather than a huge multiline macro
added test that does "nopad" encryption piece-wise, to test
replacement of EVP_CIPHER_CTX_buf_noconst
part of MDEV-29000
Summary of changes
- MD_CTX_SIZE is increased
- EVP_CIPHER_CTX_buf_noconst(ctx) does not work anymore, points
to nobody knows where. The assumption made previously was that
(since the function does not seem to be documented)
was that it points to the last partial source block.
Add own partial block buffer for NOPAD encryption instead
- SECLEVEL in CipherString in openssl.cnf
had been downgraded to 0, from 1, to make TLSv1.0 and TLSv1.1 possible
(according to https://github.com/openssl/openssl/blob/openssl-3.0.0/NEWS.md
even though the manual for SSL_CTX_get_security_level claims that it
should not be necessary)
- Workaround Ssl_cipher_list issue, it now returns TLSv1.3 ciphers,
in addition to what was set in --ssl-cipher
- ctx_buf buffer now must be aligned to 16 bytes with openssl(
previously with WolfSSL only), ot crashes will happen
- updated aes-t , to be better debuggable
using function, rather than a huge multiline macro
added test that does "nopad" encryption piece-wise, to test
replacement of EVP_CIPHER_CTX_buf_noconst
part of MDEV-28133
